While not the sole risk factor, elevated intraocular pressure is the major risk factor for the development of glaucomatous optic neuropathy. The relationship between intraocular pressure (IOP) and glaucoma is such that the risk of having or developing glaucomatous optic neuropathy, or suffering progressive damage while receiving medical therapy or following surgical treatment is directly related to the level of intraocular pressure. See, Crick, et al., Glaucoma, 7:208-219 (1995); Sommer, American Journal of Ophthalmology, Vol. 7, No. 2 (February, 1989); and Mao, et al., American Journal of Ophthalmology, Vol. 111, No. 1 (January, 1991). Additionally, a correlation exists between asymmetric damage and asymmetric IOP, Crichton, et al., Ophthalmology, Vol. 96, No. 9, (September, 1989), with the greater amount of damage observed in the eye with the higher IOP. Epidemiological surveys, such as the Baltimore Eye Survey, the Rotterdam Study, and the Barbados Eye Study have also demonstrated an increased prevalence of primary open-angle glaucoma associated with increasing IOP.
Wegner et al. (Societe Ophtalmologique Europeenne, 1997) assessed the effect of dorzolamide (a 2% topical carbonic anhydrase inhibitor) on the visual fields of patients with primary open-angle glaucoma (POAG) following one year of treatment. Visual fields were assessed using Octopus perimetry. Of the 49 patients, 39 required adjunctive IOP-lowering therapy, while only 10 were treated with dorzolamide alone.
The patients treated with dorzolaride alone had an improvement in their visual fields as determined by a decrease in the Octopus Mean Defect from 9.36 dB to 8.26 dB, and an increase in the Mean Sensitivity from 17.72 dB to 18.77 dB. The 39 patients treated with dorzolamide plus adjunctive therapy also exhibited an improvement in their visual fields as seen by a decrease in the Mean Defect from 8.07 dB to 7.52 dB, and an increase in Mean Sensitivity from 18.51 dB to 18.96 dB. Changes were reported to be significant (p&lt;0.01).
Brinzolamide is disclosed in commonly assigned U.S. Pat. Nos. 5,240,923 and 5,378,703 for its usefulness in controlling intraocular pressure, particularly in the treatment of glaucoma. These patents are incorporated herein by reference.